This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A075531 #5 Feb 20 2025 22:00:47
%S A075531 0,0,0,1,2,3,6,10,18,28,50,79,144,249,432,756
%N A075531 Number of gaps in the set of all possible values in the set X(n) given in A075529.
%H A075531 E. Ben-Naim and P. L. Krapivsky, <a href="http://arXiv.org/abs/cond-mat/0208072">Growth and Structure of Stochastic Sequences</a>, J. Phys. A (2002).
%H A075531 E. Ben-Naim, <a href="http://cnls-www.lanl.gov/People/ebn/pubs/reccur/reccur.html">Home page</a>
%e A075531 X(1) = {2} hence a(1)=0, X(2) = {3,4} hence a(2)=0, X(3) = {4,5,6,8} hence a(3)=1 because there is a gap between 6 and 8.
%K A075531 nonn,more
%O A075531 0,5
%A A075531 Eli Ben-Naim (ebn(AT)lanl.gov), Sep 19 2002
%E A075531 Entry revised by _Sean A. Irvine_, Feb 20 2025